The present invention relates to pipe hangers for suspending a pipe from an overhead support, and more particularly to a pipe hanger that is configured for suspending a pipe beneath slab foundations of concrete and reinforced steel construction.
In the construction of homes, office buildings and other such structures, it was and still is common to use a foundation of reinforced concrete prior to construction of the building superstructure. Slab-on-grade foundations are more common in warmer climates or where the soil is mostly clay. Some claim that termite issues may be less of a concern with this type of foundation, because of a lack of wood supports and empty spaces leading from the ground to the house itself. Such foundations are less expensive than elevated foundations with a crawl space or a basement.
However, slab foundations have a major disadvantage—they prevent access to the structure's environmental systems. Either the electrical wiring conduits through the slab must be water-tight, or access must be available through the attic space. Water and sewage pipes lead to disaster if they corrode or break. In some places, piping is buried under the ground below the slab and should the pipe becomes clogged or corroded an expensive excavation must take place to remove the damaged segment of the pipe.
In some areas, a problem exists where slabs settle or drop in elevation over a period of time. This problem is particularly acute in low lying areas, or in areas which have poor soil conditions. Other areas simply have a natural continuous settling of the soil, which leads to the slab foundation pressing on the pipes laid below. These pipes can settle, crack and produce explosions.
To prevent settling of pipes under slab foundations, it is desirable to affix the pipe horizontally with respect to the slab foundation so that the pipeline does not drop in elevation with respect to the slab. Conventionally, the builders use carbon steel hangers that are placed in position before the slab is poured for supporting the pipe below the slab. As the soil settles, the conventional hangers corrode and break, leaving the pipe unsupported. As a consequence, the pipes below the slab bend, crack, and deteriorate. Main sewer lines can back up causing considerable damage to the house.
To repair such broken pipes, conventional methods involve water blasting around the pipe from a street level, where the ends of the pipe are exposed. A hydro tunnel is created under the slab allowing a new pipe to be positioned under the house. The same conventional techniques are used to support the new pipe, whereby holes are punched in the slab and new supporting nails are inserted for attachment to new pipe hangers. In time, these nails will become loose, release the pipe hangers and the deterioration will start again. Needless to say this process is time consuming and expensive.
The present invention contemplates elimination of drawback associated with conventional techniques and provision of a pipe hanger assembly that can be used for suspending a pipe from an overhead support, such as for instance a concrete slab foundation.